Hoist devices are commonly used in health and care institutions for lifting particularly, but not necessarily exclusively disabled persons.
Typically the hoist device comprises a lifting column mounted on a chassis. Attached to the lifting column is a movable lifting arm which at its outer end has a sling hanger support. The person to be lifted is usually placed in a hoist sling and attachment means of the hoist sling are then connected to the sling hanger support.
To prevent accidents, such as a patient falling out of the hoist sling, it is important that the hoist sling is correctly connected to the hanger support when the patient is lifted. Moreover, it is important that the connection between the hoist sling and the hanger support is maintained, even if the patient moves considerably or suffers from spasms.
However, the connection between the hoist sling and its hanger support is occasionally and unintentionally incorrect or lost. To prevent this from happening or at least reduce the risk of it, solutions are provided for ensuring a correct and maintained connection.
JP-A-2005111113 discloses one way of ensuring proper connection between a hoist sling and a sling hanger support, which is accomplished by tension sensors arranged on the sling hanger support. More specifically, the sensors are positioned on the supporting part of four hooks belonging to the sling hanger support. During lifting, four straps of the hoist sling are located in associated hooks. Once a patient is lifted, each sensor detects a pressure applied by the corresponding strap and if at least one of the sensors does not detect any pressure, an error-signal is sent to the operator of the hoist device, allowing the lifting operation to be stopped and the straps to be correctly positioned.
U.S. Pat. No. 6,557,189 discloses another hoist device for lifting persons. However, no specific means for ensuring and verifying proper connection of a hoist sling is described.
A general problem with existing hoist devices for persons is that they do not ensure in a sufficient manner that the hoist sling is properly attached to its associated sling hanger.